There are two main reasons in real life why bombers flew high.
1) fuel efficiency
2) survivability
Altitude generally had a hit on accuracy, which is why level buffs usually went after targets which are grouped together over a certain area. Pin-point, precision bombing was next to impossible.
However, in AH most of the targets that actually effect the game are small-scale, tactical targets which need immediate attention and a quick, precision strike to take effect.
The cities and factories effect the game in a very indirect way, and require a certain precise sequence to have effect on the game. While these are in exterior, the best targets for bomber use, they offer no real meaning in terms of game play.
Therefore, people tend to strike the airbase itself - which is laid out with components that immediately effect gameplay: ordnance, fuels, barracks, FHs, VHs, BHs etc..
However, jabo runs provide a much more effective form of destruction against these targets, not to mention survivability and fun. These targets, particularly the hangars which are about the only real viable targets for bombers, respawn within 15 minutes. They need a quick, massive hit. They also immediately effect game play.
This creates a tendency for the 'casual user' who fly bombers, who have no real experience or practice in it, who just think its cool to fly one, but want to do something meaningful in it, to fly suicidal low alt runs again and again and again.
So, a combination of several factors:
1) laziness in part of the gamer(they don't want to take the time to get up to alt)
2) massive inefficiency of buffs against such small-scale tactical targets
3) no penalty or fear of death
4) immediate results can be seen without proper means
5) bases that are grouped close together, which makes fuel efficiency useless
6) weak base defenses: heavy 88mm flak is barely effective and its chance of hitting an approaching bomber is very low. light 20mm/37mm acks are too weak to shoot down buffs.
drives people to misuse the buffs.
This is in fact, not a simple problem. All of the five issues must be addressed at the same time, to see people willingly, and gladly use the bombers as they are supposed to be.
1) laziness should be inhibited by penalties against low-alt bombing
2) buffs need their targets, that effect the game play at a slow rate, but holds very serious results. A strat concept with attritional factor is needed.
3) can't do anything about the fear/death factor
4) penalties against misuse of the bombing system; ie) drops are possible only at the bombardier's position
5) strat target that is located deep inside the country, but has high impact in the game under conditions described at 2)
6) base defenses are strengthened, by implementing 88mm flak batteries around targets which players can control. Very slow rate of fire, but all the flak guns are slaved to the controller of the battery and produces a random burst of flaks, that are grouped towards the general direction the player's aim.
...
Now, imagine those conditions arise in the MA.
There's a large fuel factory deep inside enemy territory. Hitting it again and again, until total tonnage dropped on it exceeds a certain set point, will result in the decerease of available fuel supply at all enemy fields.
The buffs themselves, are optimized for high altitudes, and bomb drops are forced to be done only within the bombardier's position, which levels out the plane. Also, the bombs are armed only when it is calibrated.
Naturally, if the drop altitude is very low, its hard to calibrate stuff. Also, the bomb drop is forced at the bombsight view only, which means no squirming around or lame-prettythang dive bombings.
Also, many targets are surrounded by manned flak batteries, that are too slow firing to kill multiple nimble fighters, but can wreck havoc on a low approaching bomber formation.
...
So under these conditions, will people still think it is a worthy effort to go kamikazeing enemy bases, when it is thoroughly guarded by manned flak batteries, to hit a small sized target that stays down for only couple of hours max...
Or, will they go towards the juicy target just right for the buffs, that significantly effects the gameplay at a seriousness that is much greater than even the HQ? (also, these targets will be at least 25 miles away from the nearest airbase, so defenders can't just simply reup as soon as they die, and catch up with bombers again)
I'm thinking the latter. If we want people to fly bombers right, we need conditions that drives them to fly that way.